Why does the engine run evenly and smooth on lean mixture on carburator engine?

Tiny
XCHCUI
  • MEMBER
  • 1990 OPEL CORSA
Hello.
This question related to engine with carburator.
I would like to understand why the engine run evenly and smooth when the air/fuel mixture is lean?
I understand why the engine run evenly and smooth while the mixture is rich and why the engine run rough with too rich mixture, but I don't understand why when go from rich mixture(while the engine run evenly)to the 1:14.7 fuel/air ratio, the engine start to run rough(~ 1 lambda), but if we pass the 1:14.7 ratio into the beginning of the lean mixture area, the engine start to run evenly and smooth again?
What is happening?

Thanks in advance.
Do you
have the same problem?
Yes
No
Saturday, May 23rd, 2015 AT 7:08 AM

3 Replies

Tiny
CJ MEDEVAC
  • EXPERT
THIS HERE HAS HELPED ME MORE THAN ANYTHING IN GETTING MY CARB RIGHT. HE EXPLAINS JETTING/ POWER VALVE SELECTION/ ETC

YOU MAY HAVE TO COPY AND PASTE IT TO A NEW TAB

http://www.bob2000.com/carb.htm

HERE'S MORE SHOWING MY SET-UP/ YOU WILL SEE PICS OF MY O2 SENSOR WHICH RUNS MY AIR/ FUEL GAUGE

http://www.2carpros.com/questions/1980-jeep-cj7-new-fuel-tank-sending-unit-dash-gauge-wiring-checked-out-good-gas

THE MEDIC
Was this
answer
helpful?
Yes
No
Saturday, May 23rd, 2015 AT 5:52 PM
Tiny
XCHCUI
  • MEMBER
Thanks, CJ MEDEVAC, for the links, but nothing there explains or deal with the theory:why does the engine run evenly with rich(lambda<1, but not too rich), why the engine is not run evenly when I decrease the a mount of the fuel to get a mixture of 1 lambda, while when I decrease more the amount of fuel, to get a lean mixture(lambda>1, but not too lean)the engine, suddenly, run evenly again.
What is the theory behind that?
I read tens article about the subject, as you attached, but didn't find a good explanations, besides the fact that this is what happens.

Thanks in advance.
Was this
answer
helpful?
Yes
No
Sunday, May 24th, 2015 AT 3:05 AM
Tiny
CJ MEDEVAC
  • EXPERT
I RECKON YOU'RE GETTING SORTA TOO SCIENTIFIC FOR ME!

THIS OTHER LINK IS PROBABLY AS FAR AS I CAN TAKE YOU, MOST OF IT IS OVER MY HEAD, YOU'VE PROBABLY GANDERED OVER IT ALREADY!

http://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio

OUT OF CURIOSITY, 'ZACKLY WHAT ARE YOU DOING, AND WHAT END RESULT ARE YOU AFTER?

THE MEDIC
Was this
answer
helpful?
Yes
No
Sunday, May 24th, 2015 AT 7:15 PM

Please login or register to post a reply.

Recommended Guides